Re: [net-next PATCH v2 11/15] dt-bindings: net: dsa: qca8k: Document qca,sgmii-enable-pll

On Sat, Oct 09, 2021 at 07:13:58PM +0200, Andrew Lunn wrote:

On Fri, Oct 08, 2021 at 02:22:21AM +0200, Ansuel Smith wrote:

quoted

Document qca,sgmii-enable-pll binding used in the CPU nodes to
enable SGMII PLL on MAC config.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
---
 Documentation/devicetree/bindings/net/dsa/qca8k.txt | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/dsa/qca8k.txt b/Documentation/devicetree/bindings/net/dsa/qca8k.txt
index 208ee5bc1bbb..b9cccb657373 100644
--- a/Documentation/devicetree/bindings/net/dsa/qca8k.txt
+++ b/Documentation/devicetree/bindings/net/dsa/qca8k.txt

@@ -50,6 +50,12 @@ A CPU port node has the following optional node:
                           managed entity. See
                           Documentation/devicetree/bindings/net/fixed-link.txt
                           for details.
+- qca,sgmii-enable-pll  : For SGMII CPU port, explicitly enable PLL, TX and RX
+                          chain along with Signal Detection.
+                          This should NOT be enabled for qca8327.

So how about -EINVAL for qca8327, and document it is not valid then.

I would also add a warning. With all the ported device we found pll
needed only qca8337. I will add the error but also report the reason as
we really don't know if it does exist a qca8327 device that needs pll.
In theory not but who knows.

quoted

+                          This can be required for qca8337 switch with revision 2.

Maybe add a warning if enabled with revision < 2? I would not make it
an error, because there could be devices manufactured with a mixture
or v1 and v2 silicon. Do you have any idea how wide spread v1 is?

No idea about the revision and can't be recovered from the switch data
print on the chip. Will add a warning and put in the documentation that
we warn when an uncorrect revision is detected.

quoted

+                          With CPU port set to sgmii and qca8337 it is advised
+                          to set this unless a communication problem is observed.

  Andrew

-- 
	Ansuel